1. Field of the Invention
The present invention relates to an endoscope provided with illumination section such as an LED at the insertion section that is inserted into an object to be examined.
2. Description of Related Art
An industrial and medical endoscope is provided at the insertion section that is inserted into a lumen with an observation or imaging optical system and illumination section for illuminating around an object to be examined within the lumen. The illumination section often uses an external light source to illuminate the object via an optical fiber. In recent years, light emitting diodes (hereafter referred to as LEDs) have been provided at the insertion section to illuminate around an object to be examined (reference is made, for example, to Japanese Unexamined Patent Application, First Publication No. H10-216085, Japanese Unexamined Patent Application, First Publication No. H11-76151, and Japanese Unexamined Patent Application, First Publication No. 2002-562).
In the endoscope described in the Japanese Unexamined Patent Application, First Publication No. H10-216085 and the Japanese Unexamined Patent Application, First Publication No. H11-76151, multiple LED package chips are integrally attached to the mounting base of an adaptor detachably mounted on the distal end of the insertion section body. An LED package chip is a package including an LED bare chip plus electrodes, a fluorescent layer, a sealing layer, and the like. Coupling connectors are provided at the rear end of the adaptor and at the distal end of the insertion section body. With the connectors coupled, the LEDs are powered from a power unit in the main device. The LED package chips are attached to the front of the mounting base and soldered to one end of wires that run through the mounting base in the axial direction of the adaptor. The other ends of the wires are soldered to the connector on the adaptor.
In the above endoscope, each LED package must be soldered, leading to poor assembly workability. Particularly, assembly is troublesome when a number of LED packages are mounted.
Then, in the endoscope described in the Japanese Unexamined Patent Application, First Publication No. 2002-562, wiring is printed on the front of an insulating mounting base made, for example, of glass epoxy, and LED package chips are mounted on the mounting base and connected to the printed wiring. Electrodes on the printed wiring and electrodes at the back of the mounting base are connected via wires. In this endoscope, LED package chips are soldered to the printed wiring on the mounting base before assembly. The electrodes on the printed wiring and the electrodes at the back of the mounting base are connected during assembly, by which the wires can be reduced in number. The electrodes at the front and back of the mounting base are connected by soldering to either end of the wires that run through the mounting base. The electrodes at the back of the mounting base abut and are connected to power terminals on the insertion section body.